1. Field of the Invention
The present invention relates to moisture tempered (i.e. activated) single component polyurethane systems prepared from aromatic polyisocyanate prepolymers which are storage stable. The polyurethane elastomers prepared with said system show improved temperature resistance.
2. Description of the Art
Single component polyurethane systems are mixtures of special polyurethanes and/or polyureas forming initial compounds which in the absence of water or moisture are more or less storage stable. In the presence of water, these mixtures demonstrate a quick gel-hardening and are cold setting.
According to EP-A-No. 81729 such polyurethane-polyurea systems are used for formulating hydrolysis stable, low temperature resistant polyether urethanes, and abrasion resistant, wear protective coatings, whereby mixtures of a graft polyether polyol, an aromatic diamine and tertiary amine catalyst and organic polyisocyanate are poured or sprayed onto the surfaces, which are to be protected, using a suitable multi-component proportioning- and mixing unit. A disadvantage to this process is that often under difficult conditions on construction sites one must work with complicated and expensive mixing units, and in turn processing safety can be inadequate. This problem can be overcome through the moisture tempered, storage stable single component polyurethane systems which are described in Federal Republic of Germany Application No. 33 06 373. The systems described therein are based on isocyanate prepolymers consisting of aliphatic diisocyanates which provide polyurethanes whose mechanical properties and temperature stability could not satisfy all of the requirements for some areas of application.